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In recent years, trans-esterified vegetable oils have been widely applied to diesel engine in order to suppress greenhouse gas emissions. However, “neat” vegetable oils are expected to be directly used to resolve some difficulties faced in their use, such high viscosity and slightly high fuel consumption. In this study neat linseed oil has been investigated as a neat vegetable oil. It was found to show higher fuel consumption than diesel fuel, however at the same time it showed lower indicated fuel consumption than diesel fuel. These results suggest some increase in engine friction loss in a neat biofuel diesel engine. Studies have been extensively investigated the difference in friction loss and a newly developed “improved deceleration method” has been applied.

Recently, environmental problems come to be taken prosperously, and the reduction of environmental effects is demanded in an automobile section. The alternative fuels for diesel engines have been also developed for emission regulations. In this study, the authors proposed and estimated the validity of the hybrid system, which combines a dimethyl ether (DME) diesel engine and a DME fuel cell for commercial vehicles such as buses and tracks. DME is adopted as the both fuels for good environment and high efficiency of the system. DME has received a lot of attention recently as a possible alternative to diesel engines for a little environmental effects and stable distribution. It has the same cetane number as that of diesel fuel and emits no smoke from diesel engines. The conventional LPG stations are possible to provide DME because of the same handling as LPG.

The relation of the front wheel steering angle to the steering wheel angle in electric vehicles is changing due to the “steer-by-wire” method, which is based on an electric signal. With this method, excellent maneuverability is possible in various driving situations. Therefore, this steer control method technique is considered in this study. It was clarified that steer-bywire requires an improvement in the control stability in emergency maneuvers and the delay of counter steering in drift cornering without causing a sense of driver incompatibility. (Here, the sense of incompatibility was defined as feeling by which the harmony between the steer intention of the driver and the vehicle movement was lost.) (Here, the drift cornering shows cornering done in the area with counter steering where the rear wheel exceeded the maximum cornering force.) One control stability method is Proportional Derivative (PD) steering assistance, which is dependent on the anticipated driving situations.

In a new technology called “in wheel motor,” in which the motor is installed in the wheel, the electric vehicle can become more compact, which leads to a new type of mobility. Moreover, the front wheel steering is controlled by an electrical unit instead of the traditional mechanical unit of a steering wheel inside the car. In such a “steer-by-wire” method, the motor uses an electric signal. Because the degrees-of-freedom of this steer control are increased and a variety of steer controls based on the electric signal are possible, further improvement of the control stability is needed. In other words, the steer control technique can pose a problem for drivers, and so further research in this area is needed. That is, proportional derivative steering assistance can improve emergency evasion performance and the steering delay upon counter steering. Moreover, rear-wheel active steering can improve vehicle response during emergency evasion maneuvers.